Memory error!

[fondu-Dev]

I have written code to see if a mp3 file is readable using NSFileManager. However, this string keeps throwing the program off. A MEMORY ERROR! Take a look:

//
//  Created by Will Estes on 1/13/10.
//  Copyright 2010 Fondu Development. All rights reserved.
//

#import "DRMinizerMACAppDelegate.h"

@implementation DRMinizerMACAppDelegate

@synthesize window,statusLabel,filePath;

- (BOOL)application:(NSApplication *)sender openFile:(NSString *)path
{
	
	filePath = [[NSString alloc]init];
	filePath = path;
	
	
	
	NSLog(@"%@",filePath);
	i = 1;
	[statusLabel setStringValue:@"Song Recieved!"];
	
	return YES;
}

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
	// Insert code here to initialize your application 
}

-(IBAction)stripDRM:(id)sender {
	
	NSLog(@"%@", filePath);
	
	if(i ==1) {
		
		i = 0;
	
		[self drmbgone:filePath];
		
	}
	
	

	
}

-(void)drmbgone:(NSString *)fp {
	
	NSLog(@"drmbgone");
	
	if ( [[NSFileManager defaultManager] isReadableFileAtPath:fp] )
		NSLog(@"path is readable");
		
}

@end

You drag a mp3 file to the dock to get the program to receive the path.
When you click the UI button, it sees if its readable. BUT THE FILEPATH STRING IS GETTING ME A MEMORY ERROR.

HERE IS WHAT THE STACK SAYS:

0x00007fff8689c0b6  <+0150>  callq  0x7fff86936b04 <dyld_stub_getpid>

Program receives SIGKILL

Please help!

[smasher]

The string you get is probably set to be autoreleased, but you never retain it - so it's gone when you go to use it. Replace these two lines:

	filePath = [[NSString alloc]init];
	filePath = path;

with this one

	filePath = [path retain];

By the way what you were doing - init'ing an empty string and then throwing it away to point to a different string - doen't work the way you think it does. It's like saying this:

	a=7
	a=5

The second line cancels out the first. Also it's rare to init an empty string, since they're immutable. You can't change the string later, all you can do is point the pointer at something new.